PREVALENCE OF PRIMARY ALDOSTERONISM IN RESISTANT HYPERTENSION AND ITS ASSOCIATION WITH EARLY VASCULAR DAMAGE: PP.18.197

Abstract

Introduction: The prevalence of primary aldosteronism (PAL) is 5–10% of hypertensive subjects and even higher than in subjects affected by resistant hypertension. Aldosterone seems to play an important role in the pathogenesis of the cardiovascular damage, but few controlled clinic trials have addressed this topic. Aim: To determine the prevalence of PAL in patients with resistant hypertension, admitted in our Hypertension Unit, and define the possible association with early cardiovascular damage. Methods: Data on the first 57 patients recruited. Cardiovascular risk and early cardiovascular damage indexes (microalbuminuria and intima-media thickness of common carotid arteries) were assessed being blind for the diagnosis of PAL (plasma aldosterone (pg/ml)/PRA (ng/ml/h) ratio >400 AND plasma aldosterone >200 basally AND >100 pg/ml after acute NaCl infusion) performed after adequate pharmacological wash-out). Results: PAL was diagnosed in 20 out of 57 subjects (35.1%, aged 55.1 ± 12.6), the remaining 37 were considered affected by essential hypertension (EI, 64.9%, aged 57.4 ± 9.5). Further diagnostic investigation (adrenal CT and selected sampling from adrenal veins) was considered in patients with PAL: histological diagnosis of aldosterone-producing adenoma was obtained in 4 out of 20 subjects with PAL. The two groups did not differ for BMI, smoking habit, glycemia, LDL cholesterol, HDL cholesterol and triglyceride levels, family history of hypertension, diabetes mellitus, premature CHD. Arterial pressure levels did not differ in the two groups (PAL vs. EI: SBP 175.0 ± 24.8 vs. 169.9 ± 23.7 mmHg; DBP 104.5 ± 10.9 vs. 98.0 ± 11.7 mmHg). 10 out of 20 patients with PAL (50%) and 2 out of 37 (5.4%) patients with EI showed hypokaliemia (<3.5 mEq/l). Potassium levels were significantly lower in PAL (3.5 ± 0.5 vs. 4.0 ± 0.5 mEq/l, p = 0.0005). In subjects with PAL, microalbuminuria (52.6% vs. 21%, p = 0.02) and intima-media thickness>0.9 mm (43.7% vs. 20.7%) was statistically more frequent, although the latter was not statistically significant (p = 0.09). Conclusions: Primary aldosteronism is very frequent in the hypertensive subjects resistant to the pharmacological therapy. Among these patients, those with primary aldosteronism show an earlier vascular damage.